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Defense Travel System: Validity of Travel Payments Statistical Sampling in Question (open access)

Defense Travel System: Validity of Travel Payments Statistical Sampling in Question

Correspondence issued by the Government Accountability Office with an abstract that begins "In response to a congressional mandate to assess the reasons why the Department of Defense (DOD) is not fully in compliance with the Improper Payments Information Act of 2002 (IPIA) related to DOD travel expenditures, GAO issued two reports in 2007. In May 2007, we issued an initial report that provided an overview of DOD's IPIA reporting for fiscal years 2003 through 2006 and a discussion of the reasons reported by the DOD Office of Inspector General why the department was not in compliance with IPIA for fiscal year 2006. In December 2007, we issued our final report on our assessment of the completeness and accuracy of DOD's fiscal year 2006 IPIA disclosures related to travel expenditures, as well as DOD's planned efforts to improve and refine its processes for estimating and reporting on travel improper payments. The purpose of this letter is to bring to Congress's attention and action a matter that we discovered while preparing our final report. This letter is based on work performed during our assessment of the completeness and accuracy of DOD's fiscal year 2006 IPIA disclosures related to travel expenditures and DOD's …
Date: March 3, 2008
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library
Application of a pilot control banding tool for risk level assessment and control of nanoparticle exposures (open access)

Application of a pilot control banding tool for risk level assessment and control of nanoparticle exposures

Control Banding (CB) strategies offer simplified solutions for controlling worker exposures to constituents that are found in the workplace in the absence of firm toxicological and exposure data. These strategies may be particularly useful in nanotechnology applications, considering the overwhelming level of uncertainty over what nanomaterials and nanotechnologies present as potential work-related health risks, what about these materials might lead to adverse toxicological activity, how risk related to these might be assessed, and how to manage these issues in the absence of this information. This study introduces a pilot CB tool or 'CB Nanotool' that was developed specifically for characterizing the health aspects of working with engineered nanoparticles and determining the level of risk and associated controls for five ongoing nanotechnology-related operations being conducted at two Department of Energy (DOE) research laboratories. Based on the application of the CB Nanotool, four of the five operations evaluated in this study were found to have implemented controls consistent with what was recommended by the CB Nanotool, with one operation even exceeding the required controls for that activity. The one remaining operation was determined to require an upgrade in controls. By developing this dynamic CB Nanotool within the realm of the scientific information …
Date: March 3, 2008
Creator: Paik, S Y; Zalk, D M & Swuste, P
Object Type: Article
System: The UNT Digital Library
Cfd Modeling Analysis of Mechanical Draft Cooling Tower (open access)

Cfd Modeling Analysis of Mechanical Draft Cooling Tower

Industrial processes use mechanical draft cooling towers (MDCT's) to dissipate waste heat by transferring heat from water to air via evaporative cooling, which causes air humidification. The Savannah River Site (SRS) has a MDCT consisting of four independent compartments called cells. Each cell has its own fan to help maximize heat transfer between ambient air and circulated water. The primary objective of the work is to conduct a parametric study for cooling tower performance under different fan speeds and ambient air conditions. The Savannah River National Laboratory (SRNL) developed a computational fluid dynamics (CFD) model to achieve the objective. The model uses three-dimensional steady-state momentum, continuity equations, air-vapor species balance equation, and two-equation turbulence as the basic governing equations. It was assumed that vapor phase is always transported by the continuous air phase with no slip velocity. In this case, water droplet component was considered as discrete phase for the interfacial heat and mass transfer via Lagrangian approach. Thus, the air-vapor mixture model with discrete water droplet phase is used for the analysis. A series of the modeling calculations was performed to investigate the impact of ambient and operating conditions on the thermal performance of the cooling tower when fans …
Date: March 3, 2008
Creator: Lee, S.; Alfred Garrett, A.; James02 Bollinger, J. & Larry Koffman, L.
Object Type: Article
System: The UNT Digital Library
Development and Testing of a Life Cycle Model and a Parameterization of Thin Mid-level Stratiform Clouds (open access)

Development and Testing of a Life Cycle Model and a Parameterization of Thin Mid-level Stratiform Clouds

We used a cloud-resolving model (a detailed computer model of cloud systems) to evaluate and improve the representation of clouds in global atmospheric models used for numerical weather prediction and climate modeling. We also used observations of the atmospheric state, including clouds, made at DOE's Atmospheric Radiation Measurement (ARM) Program's Climate Research Facility located in the Southern Great Plains (Kansas and Oklahoma) during Intensive Observation Periods to evaluate our detailed computer model as well as a single-column version of a global atmospheric model used for numerical weather prediction (the Global Forecast System of the NOAA National Centers for Environmental Prediction). This so-called Single-Column Modeling approach has proved to be a very effective method for testing the representation of clouds in global atmospheric models. The method relies on detailed observations of the atmospheric state, including clouds, in an atmospheric column comparable in size to a grid column used in a global atmospheric model. The required observations are made by a combination of in situ and remote sensing instruments. One of the greatest problems facing mankind at the present is climate change. Part of the problem is our limited ability to predict the regional patterns of climate change. In order to increase …
Date: March 3, 2008
Creator: Krueger, Steven K.
Object Type: Report
System: The UNT Digital Library
Spatial Variability of Reactive Mineral and Radionuclide Kd Distributions in the Tuff Confining Unit: Yucca Flat, Nevada Test Site (open access)

Spatial Variability of Reactive Mineral and Radionuclide Kd Distributions in the Tuff Confining Unit: Yucca Flat, Nevada Test Site

None
Date: March 3, 2008
Creator: Carle, S F; Zavarin, M & Pawloski, G A
Object Type: Report
System: The UNT Digital Library
PREDICTION OF SURFACE SETTLEMENT DUE TO THE DISPLACEMENT OF SOFT ZONES (open access)

PREDICTION OF SURFACE SETTLEMENT DUE TO THE DISPLACEMENT OF SOFT ZONES

In areas composed of coastal plain sediments, soft zones subjected to partial overburden may be present in the subsurface. During or after a seismic event, these soft zones may be compressed. The resulting displacement due to the deformation of the soft zones will propagate to the ground surface and cause the surface to settle. This paper presents a method to predict the settlement at the surface due to the propagation of the displacement from the soft zones. This method is performed by discretizing the soft zones into multiple clusters of finite sub-areas or subspaces. Settlement profile at the ground surface due to the displacement of each sub-area or subspace is computed assuming the shape is a normal distribution function. Settlement due to the displacement of the soft zones can then be approximated by adding the settlements computed for all the sub-areas or subspaces. This method provides a simple and useful tool for the prediction of the settlement profile and the results are consistent with those obtained from the finite difference analysis.
Date: March 3, 2008
Creator: Li, W
Object Type: Article
System: The UNT Digital Library
Remaining Sites Verification Package for the 100-F-26:13, 108-F Drain Pipelines, Waste Site Reclassification Form 2005-011 (open access)

Remaining Sites Verification Package for the 100-F-26:13, 108-F Drain Pipelines, Waste Site Reclassification Form 2005-011

The 100-F-26:13 waste site is the network of process sewer pipelines that received effluent from the 108-F Biological Laboratory and discharged it to the 188-F Ash Disposal Area (126-F-1 waste site). The pipelines included one 0.15-m (6-in.)-, two 0.2-m (8-in.)-, and one 0.31-m (12-in.)-diameter vitrified clay pipe segments encased in concrete. In accordance with this evaluation, the verification sampling results support a reclassification of this site to Interim Closed Out. The results of verification sampling demonstrated that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also showed that residual contaminant concentrations are protective of groundwater and the Columbia River.
Date: March 3, 2008
Creator: Dittmer, L. M.
Object Type: Report
System: The UNT Digital Library
A Unified Monte Carlo Approach to Fast Neutron Cross Section Data Evaluation. (open access)

A Unified Monte Carlo Approach to Fast Neutron Cross Section Data Evaluation.

A unified Monte Carlo (UMC) approach to fast neutron cross section data evaluation that incorporates both model-calculated and experimental information is described. The method is based on applications of Bayes Theorem and the Principle of Maximum Entropy as well as on fundamental definitions from probability theory. This report describes the formalism, discusses various practical considerations, and examines a few numerical examples in some detail.
Date: March 3, 2008
Creator: Smith, D.
Object Type: Report
System: The UNT Digital Library
Estimating solar access of typical residential rooftops: A case study in San Jose, CA (open access)

Estimating solar access of typical residential rooftops: A case study in San Jose, CA

Shadows cast by trees and buildings can limit the solar access of rooftop solar-energy systems, including photovoltaic panels and thermal collectors. This study characterizes rooftop shading in a residential neighborhood of San Jose, CA, one of four regions analyzed in a wider study of the solar access of California homes.High-resolution orthophotos and LiDAR (Light Detection And Ranging) measurements of surface height were used to create a digital elevation model of all trees and buildings in a 4 km2 residential neighborhood. Hourly shading of roofing planes (the flat elements of roofs) was computed geometrically from the digital elevation model. Parcel boundaries were used to determine the extent to which roofing planes were shaded by trees and buildings in neighboring parcels.In the year in which surface heights were measured (2005), shadows from all sources ("total shading") reduced the insolation received by S-, SW-, and W-facing residential roofing planes in the study area by 13 - 16percent. Shadows cast by trees and buildings in neighboring parcels reduced insolation by no more than 2percent. After 30 years of simulated maximal tree growth, annual total shading increased to 19 - 22percent, and annual extraparcel shading increased to 3 - 4percent.
Date: March 3, 2008
Creator: Levinson, Ronnen M.; Gupta, Smita; Akbari, Hashem & Pomerantz, Melvin
Object Type: Article
System: The UNT Digital Library
An Investigation of the Effect of Graphite Degradation on the Irreversible Capacity in Lithium-ion Cells (open access)

An Investigation of the Effect of Graphite Degradation on the Irreversible Capacity in Lithium-ion Cells

The effect of surface structural damage on graphitic anodes, commonly observed in tested Li-ion cells, was investigated. Similar surface structural disorder was artificially induced in Mag-10 synthetic graphite anodes using argon-ion sputtering. Raman microscopy, scanning electron microscopy (SEM) and Brunauer Emmett Teller (BET) measurements confirmed that Ar-ion sputtered Mag-10 electrodes display similar degree of surface degradation as the anodes from tested Li-ion cells. Artificially modified Mag-10 anodes showed double the irreversible charge capacity during the first formation cycle, compared to fresh un-altered anodes. Impedance spectroscopy and Fourier transform infrared (FTIR) spectroscopy on surface modified graphite anodes indicated the formation of a thicker and slightly more resistive SEI layer. Gas chromatography/mass spectroscopy (GC/MS) analysis of solvent extracts from the electrodes detected the presence of new compounds with M{sub w} on the order of 1600 g mol{sup -1} for the surface modified electrode with no evidence of elevated M{sub w} species for the unmodified electrode. The structural disorder induced in the graphite during long-term cycling maybe responsible for the slow and continuous SEI layer reformation, and consequently, the loss of reversible capacity due to the shift of lithium inventory in cycled Li-ion cells.
Date: March 3, 2008
Creator: Stevenson, Cynthia; Hardwick, Laurence J.; Marcinek, Marek; Beer, Leanne; Kerr, John B. & Kostecki, Robert
Object Type: Article
System: The UNT Digital Library
Unraveling duality violations in hadronic tau decays (open access)

Unraveling duality violations in hadronic tau decays

There are some indications from recent determinations of the strong coupling constant alpha_s and the gluon condensate that the Operator Product Expansion may not be accurate enough to describe non-perturbative effects in hadronic tau decays. This breakdown of the Operator Product Expansion is usually referred to as being due to"Duality Violations." With the help of a physically motivated model, we investigate these duality violations. Based on this model, we argue how they may introduce a non-negligible systematic error in the current analysis, which employs finite-energy sum rules with pinched weights. In particular, this systematic effect might affect the precision determination of alpha_s from tau decays. With a view to a possible future application to real data, we present an alternative method for determining the OPE coefficients that might help estimating, and possibly even reducing, this systematic error.
Date: March 3, 2008
Creator: Cata, Oscar; Cata, Oscar; Golterman, Maarten & Peris, Santiago
Object Type: Article
System: The UNT Digital Library
The Design, Construction, and Operation of Long-Distance High-Voltage Electricity Transmission Technologies. (open access)

The Design, Construction, and Operation of Long-Distance High-Voltage Electricity Transmission Technologies.

This report focuses on transmission lines, which operate at voltages of 115 kV and higher. Currently, the highest voltage lines comprising the North American power grid are at 765 kV. The grid is the network of transmission lines that interconnect most large power plants on the North American continent. One transmission line at this high voltage was built near Chicago as part of the interconnection for three large nuclear power plants southwest of the city. Lines at this voltage also serve markets in New York and New England, also very high demand regions. The large power transfers along the West Coast are generally at 230 or 500 kV. Just as there are practical limits to centralization of power production, there are practical limits to increasing line voltage. As voltage increases, the height of the supporting towers, the size of the insulators, the distance between conductors on a tower, and even the width of the right-of-way (ROW) required increase. These design features safely isolate the electric power, which has an increasing tendency to arc to ground as the voltage (or electrical potential) increases. In addition, very high voltages (345 kV and above) are subject to corona losses. These losses are a …
Date: March 3, 2008
Creator: Molburg, J. C.; Kavicky, J. A. & Picel, K. C.
Object Type: Report
System: The UNT Digital Library
A Multi-Layered Ceramic Composite for Impermeable Fuel Cladding for COmmercial Wate Reactors (open access)

A Multi-Layered Ceramic Composite for Impermeable Fuel Cladding for COmmercial Wate Reactors

A triplex nuclear fuel cladding is developed to further improve the passive safety of commercial nuclear plants, to increase the burnup and durablity of nuclear fuel, to improve the power density and economics of nuclear power, and to reduce the amount of spent fuel requiring disposal or recycle.
Date: March 3, 2008
Creator: Feinroth, Herbert
Object Type: Report
System: The UNT Digital Library
On the Long-Term Average Cost of CO2 Transport and Storage (open access)

On the Long-Term Average Cost of CO2 Transport and Storage

Paper describes general trends in the cost of CO2 transport and storage (including measurement, monitoring, and verification) and how these can be used to justify a proxy cost to cover a large number of potential CCS commercial deployment scenarios.
Date: March 3, 2008
Creator: Dooley, James J.; Dahowski, Robert T. & Davidson, Casie L.
Object Type: Report
System: The UNT Digital Library
Pulse Jet Mixer Overblow Testing for Assessment of Loadings During Multiple Overblows (open access)

Pulse Jet Mixer Overblow Testing for Assessment of Loadings During Multiple Overblows

The U.S. Department of Energy (DOE) Office of River Protection’s Waste Treatment Plant (WTP) is being designed and built to pretreat and then vitrify a large portion of the wastes in Hanford’s 177 underground waste storage tanks. The WTP consists of three primary facilities: pretreatment, low-activity waste (LAW) vitrification, and high-level waste (HLW) vitrification. The pretreatment facility will receive waste feed from the Hanford tank farms and separate it into 1) a high-volume, low-activity liquid stream stripped of most solids and radionuclides and 2) a much smaller volume of HLW slurry containing most of the solids and most of the radioactivity. Many of the vessels in the pretreatment facility will contain pulse jet mixers (PJMs) that will provide some or all of the mixing in the vessels. This technology was selected for use in so-called “black cell” regions of the WTP, where maintenance capability will not be available for the operating life of the WTP. PJM technology was selected for use in these regions because it has no moving mechanical parts that require maintenance. The vessels with the most concentrated slurries will also be mixed with air spargers and/or steady jets in addition to the mixing provided by the PJMs. …
Date: March 3, 2008
Creator: Pfund, David M.; Bontha, Jagannadha R.; Michener, Thomas E.; Nigl, Franz; Yokuda, Satoru T.; Leigh, Richard J. et al.
Object Type: Report
System: The UNT Digital Library
Accelerator mass spectrometry of Strontium-90 for homeland security, environmental monitoring, and human health (open access)

Accelerator mass spectrometry of Strontium-90 for homeland security, environmental monitoring, and human health

Strontium-90 is one of the most hazardous materials managed by agencies charged with protecting the public from radiation. Traditional radiometric methods have been limited by low sample throughput and slow turnaround times. Mass spectrometry offers the advantage of shorter analysis times and the ability to measure samples immediately after processing, however conventional mass spectrometric techniques are susceptible to molecular isobaric interferences that limit their overall sensitivity. In contrast, accelerator mass spectrometry is insensitive to molecular interferences and we have therefore begun developing a method for determination of {sup 90}Sr by accelerator mass spectrometry. Despite a pervasive interference from {sup 90}Zr, our initial development has yielded an instrumental background of {approx} 10{sup 8} atoms (75 mBq) per sample. Further refinement of our system (e.g., redesign of our detector, use of alternative target materials) is expected to push the background below 10{sup 6} atoms, close to the theoretical limit for AMS. Once we have refined our system and developed suitable sample preparation protocols, we will utilize our capability in applications to homeland security, environmental monitoring, and human health.
Date: March 3, 2008
Creator: Tumey, S J; Brown, T A; Hamilton, T F & Hillegonds, D J
Object Type: Article
System: The UNT Digital Library
Trade Preferences for Developing Countries and the WTO (open access)

Trade Preferences for Developing Countries and the WTO

This report discusses the trade preferences and General Agreement on Tariffs and Trade (GATT) most-favored-nation (MFN) requirements, World Trade Organization (WTO) waivers for preferential trade agreements, and WTO waivers for U.S. preference programs.
Date: March 3, 2008
Creator: Grimmett, Jeanne J.
Object Type: Report
System: The UNT Digital Library
[E-mail from Ken Whalen to Publisher at TDNA, March 3, 2008] (open access)

[E-mail from Ken Whalen to Publisher at TDNA, March 3, 2008]

E-mail from Ken Whalen to the Publisher of TDNA, cc'd to Darla Thompson, with the subject Public Notice Website FAX. The e-mail is in regards to the TDNA faxing a form to their office asking for information for the new public notice website they have developed with the Texas Press Association.
Date: March 3, 2008
Creator: Whalen, Ken
Object Type: Letter
System: The UNT Digital Library
Predictions of H-mode performance in ITER (open access)

Predictions of H-mode performance in ITER

Time-dependent integrated predictive modeling is carried out using the PTRANSP code to predict fusion power and parameters such as alpha particle density and pressure in ITER H-mode plasmas. Auxiliary heating by negative ion neutral beam injection and ion cyclotron heating of He3 minority ions are modeled, and the GLF23 transport model is used in the prediction of the evolution of plasma temperature profiles. Effects of beam steering, beam torque, plasma rotation, beam current drive, pedestal temperatures, sawtooth oscillations, magnetic diffusion, and accumulation of He ash are treated self-consistently. Variations in assumptions associated with physics uncertainties for standard base-line DT H-mode plasmas (with Ip=15 MA, BTF=5.3 T, and Greenwald fraction=0.86) lead to a range of predictions for DT fusion power PDT and quasi-steady state fusion QDT (≡ PDT/Paux). Typical predictions assuming Paux = 50-53 MW yield PDT = 250- 720 MW and QDT = 5 - 14. In some cases where Paux is ramped down or shut off after initial flat-top conditions, quasi-steady QDT can be considerably higher, even infinite. Adverse physics assumptions such as existence of an inward pinch of the helium ash and an ash recycling coefficient approaching unity lead to very low values for PDT. Alternative scenarios with …
Date: March 3, 2008
Creator: R.V. Budny, R.Andre, G.Bateman, F.Halpern, C.E.Kessel, A.Kritz, and D.McCune
Object Type: Report
System: The UNT Digital Library
Improving the Performance of Lithium Manganese Phosphate Through Divalent Cation Substitution (open access)

Improving the Performance of Lithium Manganese Phosphate Through Divalent Cation Substitution

Highly crystalline samples of LiMnPO{sub 4} and its analogs with partial substitution of Mn by divalent Mg, Cu, Zn, and Ni were prepared by hydrothermal synthesis and characterized by x-ray diffraction and infrared spectroscopy. Chemical oxidation produced two-phase mixtures of the initial phases LiMn{sub (1-y)}M{sub y}PO{sub 4} and the delithiated forms, Li{sub y}Mn{sub (1-y)}M{sub y}PO{sub 4}, all with the olivine structure. The extent of oxidation depended upon the quantity of oxidizing agent used and on the identity of the substituent ions. Mg, Ni and Cu were found to increase the level of delithation relative to that in pure LiMnPO{sub 4}. Mg was also shown to reduce the tendency of the oxidized phase to absorb water.
Date: March 3, 2008
Creator: Chen, Guoying & Richardson, Thomas J.
Object Type: Article
System: The UNT Digital Library
The Baytown Sun (Baytown, Tex.), Vol. 88, No. 63, Ed. 1 Monday, March 3, 2008 (open access)

The Baytown Sun (Baytown, Tex.), Vol. 88, No. 63, Ed. 1 Monday, March 3, 2008

Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.
Date: March 3, 2008
Creator: Clements, Clifford E.
Object Type: Newspaper
System: The Portal to Texas History
Small Business Tax Benefits: Overview and Economic Rationales (open access)

Small Business Tax Benefits: Overview and Economic Rationales

None
Date: March 3, 2008
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Traditional and Roth Individual Retirement Accounts (IRAs): A Primer (open access)

Traditional and Roth Individual Retirement Accounts (IRAs): A Primer

None
Date: March 3, 2008
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Navy Role in Global War on Terrorism (GWOT) — Background and Issues for Congress (open access)

Navy Role in Global War on Terrorism (GWOT) — Background and Issues for Congress

None
Date: March 3, 2008
Creator: unknown
Object Type: Report
System: The UNT Digital Library